1. Field of the Invention
The invention relates to a method of switching between video signal sin an image switching apparatus which has a switch for switching between a video signal supplied by a camera and a video signal supplied by a recording apparatus, and which has a circuit for processing the video signal coming from the recording apparatus.
2. Description of Related Art
Such a method for an image switching apparatus used in surveillance or monitoring systems, e.g. in stores, hotels or underground car parks, is known from U.S. Pat. No. 5,150,212. The image switching apparatus works in two operating modes. The first operating mode is a recording mode, the second operating mode is a replay mode. In the recording mode, a control unit controls a switch to which the video signals of several cameras are connected. Individual images are filtered out from the video signals, given an address and recorded. The address identifies the camera. In the second operating mode a signal reproduced by the video recorder is detected from the address and delivered as an output to a corresponding monitor belonging to the camera. The circuit is of a complicated construction.
Such a method for an image switching apparatus is also known from WO 99/49 659. A video recorder is provided with an activation unit by means of which the image switching apparatus can be controlled into a first recording mode or a second replay mode. Adjustment means within the image switching apparatus set the operating mode to the record mode when a camera switching signal is received from the recorder, and to the replay mode when an address signal is detected within the video signal coming from the recorder. The circuit of the image switching apparatus is of a complicated construction.